If there is supply of city gas in your flat this article is VERY IMPORTANT.
In Spain you must notify gas consumption to energy companies. In your apartment you will find a gas consumption meter as you can see in the picture. The gas meter is usually outside the kitchen window or under the sink.
Each two month you will see a red color sheet in the lobby of your building. You should write on it your consumption because, with that information, the company performs bill. If you leave blank the red sheet, bill arrives with a minimum price but does not include the cost of the consumption made.
It is really important to fill this sheet of the lobby because Emancipia will not return the security deposits to the tenants if the last gas bill which sent the company does not have included the cost of consumptions. So if no one of you on the flat write the consumption measure in the sheet of the lobby, return of the deposit may not be at the time of your departure but several months later. Please, stay tuned to the sheet of the lobby.